﻿<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8" />
    <title>运算符优先级</title>
</head>
<body>
    <script language="javascript">
        let a = 3 + 4 * 5;        //按照自动优先级进行
        let b = (3 + 4) * 5;      //用()改变运算优先级
        alert("3+4*5=" + a + "\n(3+4)*5=" + b); //分行输出结果
    </script>
</body>
</html>